Magnetic sound recording device



July 28, 1942. A. STAPELFELDT MAGNETIC SOUND RECORDING DEVICE Filed Aug. 4, 1939 fivauverwe Mar-0e CUBEENT Jooece Moro/8.

r- ]"'T n Pan/5Q) Patented .iuly 28, 1942 accuses MAGNETIC SOUND miconnmc navron Arnold Stapelfeldt, Berlin, Germany, asslgnor to C. Lorenz Aktiengesellschaft, Berlin-Tempelhot, Germany, a company Application August 4, 1939, Serial No. 288,333 In Germany August 4, 1938 Claims. (or. 192-143) Magnetic recording devices of the type designated as steeltone machines are known which comprise a mechanism coupled with the motor drive and having a hand or pointer for indicating I the length of that part of the wireor tapeindicating device of the type having rotary-pointers are employed. Furthermore marker plates have been used which have a nut screw in engagement with a spindle or lead screw and arranged to move along this spindle under the influence of a guide rod for such nut. This rod is mounted on a casing in which the well-known bobbins or reels are contained, and is displaceable in its longitudinal direction. When now the nut comes against an adjusting ring the guide rod is displaced and thereby acts to stop the machine. Su'ch an arrangement is shown, for example, in my copending application Ser. No. 277,780 filed June 9, 1939. This arrangement has the disadvantage that the machine will be stopped by every impact influencing it and will be stopped also whenever the guide rod is touched.

.and thereby to stop the machine.

An embodiment of this kind is described hereafter, by way of example, reference being bad to the accompanying drawing in which Fig. 1 is a fragmentary sectional View thereof while Fig. 2 shows a section on line E -2 of Fig. 1.

i denotes a casing in which the well-known reels, not represented in the drawing, are located. A lead screw or spindle 2 is revolubly mounted in the casing i and is connected with a motor drive A which comprises two bevel gears, as shown. Spindle 2 is in engagement with a nut screw 3 guided in a slot 1) of the casing 9. Nut 3 carries a pointer it that belongs to a. scale l5 which extends longitudinally of the casing. The nut 3 also has two stops 4, 5 rigidly fitted to it. Two adjustable slides G, l are guided in a longitudinal slot 0 of casing l and have each a lever t, 514 fulcrumed to them. These levers are ar- I ranged to be deflected by the stops t, 5, respectively. One of the levers 8, 9 serves to stop the machine upon its forward limit of operation, while the other lever is to limit the recoiling length. The levers 8, 9 to such end act on two flaps IO, N, mounted in the casing l by means of a trunnion at common to them. The flaps I0, H have each an arm I3 and I2, respectively. These arms are arranged to close contacts e, f and thereby to stop the machine in any well known manner, for example, by stopping the motor or opening a driving clutch. Such stoppage will thus occur whenever either ,flap 10 or flap H is turned by lever 9 or 8, respectively, these levers being actuated by the stops 4, 5, as before described. Slide 6 may be displaced in slot 0 to limit the operating time of the machine to a desired time of talking. Equally, slide 1 allows of limiting the recoiling period in accordance with each speech. For instance, in case it is desired to repeat a recorded speech, slide 1 may be so adjusted that the machine shall only recoil until the commencement of the desired speech. Much time will thus be saved, since it is not necessary to recoil the whole record carrier.

Another advantage is that the machine will not be affected by shocks and will not be stopped accidentally.

To provide for a remote indication of the successive positions of the record carrier a potentiometer may be arranged parallel to spindle 2 and the nut 3 may be equipped with a contact member for such potentiometer. The various positions this contact member assumes when traveling along the potentiometer, and which accord with the successive positions of pointer id and equally accord with the record-carryin Portion of the recording wire or tape, may then be transmitted in known manner to a remote place.

What is claimed is:

l. A. sound recording machine which comprises a drive means, a rectilinear scale, adjustable slides adapted to be displaced in both directions of this scale, levers fulcrumed to these slides, movable stops to deflect these levers, means controlled by said drive means for moving said stops along said scale and into operative position with respect to said levers, flaps arranged to move under the control of deflection of said levers, and electric contacts to efi'ect the stoppage of the machine, such contacts being under the control of movement said flaps.

2. A sound recording machine according to 4. A sound recording machine according to claim 1, in which the said flaps are mounted in the casing by means or a trunnion common to them.

5. A sound recording machine according to claim 1, having arms rigid with said flaps to operate the said contacts.

ARNOLD STAPELFELDT. 

